The kids in this painting, thought to be the daughter and son of Sir Richard Lloyd of Hintlesham Hall, near Ipswich, are outshone by the sky. Not that it is bright, exactly. A silky riot of black rainclouds and silver sunlit tones hangs over the Lloyd estate on a day of ripe East Anglian gloom. Gainsborough doesn’t just paint clouds but the air between us and them, capturing an uneasy, almost electrical glow in the atmosphere. The fluffy leaves of the trees are set off sharply against this bronze light. The clouds are reflected in the lake, adding to all the greys and ivories. This wet British day gives the classical balustrade against which the children pose a poetic gravity that ennobles their pale faces and casual clothes. They seem suitably brooding for this place. Perhaps they will grow up to be Romantic poets.